%0 Journal Article %A Naeem, Karattu Chali %A Neenu, Kadaikkara %A Nair, Vijayakumar C. %D 2017 %T Effect of Differential Self-Assembly on Mechanochromic Luminescence of Fluorene-Benzothiadiazole-Based Fluorophores %U https://acs.figshare.com/articles/journal_contribution/Effect_of_Differential_Self-Assembly_on_Mechanochromic_Luminescence_of_Fluorene-Benzothiadiazole-Based_Fluorophores/5715889 %R 10.1021/acsomega.7b01339.s001 %2 https://acs.figshare.com/ndownloader/files/10035553 %K Fluorene-Benzothiadiazole-Based Fluorophores Supramolecular self-assembly %K mechanoresponsive luminescence %K Differential Self-Assembly %K fluorene-benzothiadiazole-based fluorophores %K Differential self-assembly %K nonpolar solvents %K UV %K self-assembled state %K molecules self-assemble %K FB-C 6 %K alkyl chain length %K fluorescence spectroscopy %K scanning electron microscopy %K Mechanochromic Luminescence %K X-ray diffraction spectroscopy %K fluorene moiety %K time-correlated single-photon %K FB-C 12 %K alkyl chains %K donor %K excitation energy migration properties %K mechanochromic luminescence properties %K hydrogen-bonding amide groups %X Supramolecular self-assembly is an excellent tool for controlling the optical and electronic properties of chromophore-based molecular systems. Herein, we demonstrate how differential self-assembly affects mechanoresponsive luminescence of fluorene-benzothiadiazole-based fluorophores. We have synthesized two donor–acceptor–donor-type conjugated oligomers consisting of fluorene as the donor and benzothiadiazole as the acceptor. For facile self-assembly, both molecules are end-functionalized with hydrogen-bonding amide groups. Differential self-assembly was induced by attaching alkyl chains of different lengths onto the fluorene moiety: hexyl (FB-C6) and dodecyl (FB-C12). The molecules self-assemble to form well-defined nanostructures in nonpolar solvents and solvent mixtures. Although their optical properties in solution are not affected by the alkyl chain length, significant effects were observed in the self-assembled state, particularly in the excitation energy migration properties. As a result, remarkable differences were observed in the mechanochromic luminescence properties of the molecules. A precise structure–property correlation is made using UV–visible absorption and fluorescence spectroscopy, time-correlated single-photon counting analysis, scanning electron microscopy, and X-ray diffraction spectroscopy. %I ACS Publications